Already been done, so you might say that I’m qualified.
Government spending cannot selectively target prices. This means that while some inputs will be brought up to their “older” level of demand. Some prices will go up a lot, others a little. This means that some prices will rise, but it will not rise to normal demand. Aggregate demand doesn’t exist, only specific demand exists. Furthermore, how is it that, even once demand returns to normal and government spending is cut that the recession will not return?
Finally, while government spending can increase demand in perverse, wasteful, and temporary directions, it will oftentimes increase regime uncertainty which will decrease business activity in a period of uncertainty which is already great. Most import importantly the expectation of the government propping up prices will prevent prices from readjusting to the necessary levels at which point full employment will come about. Government spending makes prices and wages sticky and elongate the readjustment period. There is absolutely zero reason to believe that prices on a free market are sticky, especially over time, so we would expect prices to adjust quickly on the free market and for normal ratios to be restored.